Railroad switch heater



H. J. HIRSCHHORN ET AL 3,433,943

RAILROAD SWITCH HEATER March 18, 1969 Sheet of 5 Filed April 12, 1966INVENTORS' N mm s Hm H mm N A% MRMVO H r .6 T u A J m HM} M March 18,1969 H. J. HIRSCHHORN ET AL 3,433,943

RAILROAD SWITCH HEATER Filed April 12, 1966 Sheet 2 I ENTORS HARRYCHHORN TORNEY March 18, 1969 H. J. HIRSCHHORN ET AL 3,433,943

RAILROAD SWITCH HEATER Sheet Filed April 12, 1966 No wmw W O F THH/ $5mm J WM H M f ATTORNEYS United States Patent 3,433,943 RAILROAD SWITCHHEATER Harry J. Hirschhorn and John G. Rachford, Chicago, Ill.,assignors to Midwesco-Enterprise, Inc., a corporation of Illinois FiledApr. 12, 1966, Ser. No. 541,993 U.S.'Cl. 246-428 11 Claims Int. Cl. E01b7/24 ABSTRACT OF THE DISCLOSURE A heater for melting ice and snow fromrailway switching rails. Combustible gas is released at intervals insidean'elongated burner chamber made up of a surrounding hood and platewhich are spaced apart to form an air intake opening along the bottom ofthe chamber and an upper combustion throat adjacent the rail to beheated. A shield adjacent the chamber provides protection against flameout due to wind gusts.

This invention relates to an improved arrangement for melting ice andsnow which may collect around the moving and fixed rails of railwaytrack switching apparatus.

Ice and snow which collects between and around the movable points of arailroad switch, if accumulated in suflicient quantity, may render theswitch inoperable. Manual removal of such an accumulation is a laborioustask consuming a substantial amount of time during which the switchingyard is out of operation. Rail heating arrangements have accordinglybeen devised in order to melt the accumulated ice and snow and toprevent such accumulation.

In conventional rail heating systems, high pressure gas is piped alongthe rail and openings in the gas-carrying conduit direct gas jets towardthe ball and web of the rail. The use of high pressure gas enables theflame to be accurately directed even in the presence of wind currents.

High pressure heating systems do, however, possess significantdisadvantages. Combustible gas is normally not available at highpressures at the railroad yard; consequently, auxiliary equipment mustoften be used to increase the pressure of the gas supplied to the railheaters. The localized, high-intensity flames produced in a highpressure system create a possibility that the flames may ignite adjacentrailroad ties or inflammable portions of rolling stock which may parkover the burners.

It is accordingly an object of the present invention to provide animproved, low-pressure railway switch heater which produces an evenlydistributed, gentle flame along the length of the rail.

Low pressure heating systems have heretofore been subject to flame-outcaused by wind currents and turbulence. Such flame-outs render theburner temporarily inoperative until the gas can be re-ignited. Inaddition, because the combustible gas used may be heavier than air, theunburned gas may form in pools thereby creating a fire hazard.

It is accordingly a further object of the invention to provide animproved low-pressure railroad switch heater which is substantiallyimmune to flame-out caused by wind currents and turbulence.

In the principal aspect, the present invention takes the form of anarrangement for melting collected ice and snow from railway switchingrails. A gas carrying conduit spaced apart from and substantiallyparallel to the rail to be heated is supplied with low-pressure gas. Jetholes drilled at intervals along the conduit supply the unburned gas toa burner chamber formed by a surrounding hood and plate. Thecross-sectional shape of the burner hood may take the form of aninverted-J in which the arcuate ice portion of the hood surrounds and isspaced from the conduit and the downwardly depending portion of the hoodis positioned to extend below the conduit. A burner plate is mounted atan angle to and spaced from the downwardly depending portion of the hoodto form an intake air opening between the bottom edge of the plate andthe downwardly extending portion of the hood. According to a feature ofthe invention, the upper edge of the plate is parallel with and isspaced from the edge of the arcuate portion of the hood to form alongitudinal venturi throat adjacent to the rail. This venturi throatdirects the flame to the ball and web of the rail, tends to hold theflame against blow out, and produces a short, intense flame. Accordingto a further feature of the invention, a burner shield lying in a planesubstantially parallel to the plane of the downwardly depending portionof the hood and spaced apart from the hood allows air to enter theburner chamber but provides protection against wind currents. The burnershield enhances the heating ability of the arrangement by causingrecirculation of the heated combustion products of the flame to shortenthe flame and increase the burning efliciently. According to a stillfurther feature of the invention, spacing members placed at intervalsbetween the burner hood and burner plate insure precise aperture widthsfor both the venturi throat and the air intake.

Ignition of the gas-air mixture appearing at the venturi throat isaccomplished even in high winds by the provision of an ignition cup. Araw pilot-gas jet is injected into the cup so that turbulent mixingoccurs. A spark plug, glow coils, or other form of igniter may beemployed to produce the initial flame within the ignition cup, whichthen propagates along the length of the venturi throat. Means may beemployed for re-energizing the igniter in response to any flame loss.

These and other features, objects and advantages of the presentinvention may be more clearly understood by considering the followingdetailed description. In the course of this description, reference willbe frequently made to the attached drawings in which:

FIGURE 1 is an exploded perspective view of a switching rail heaterwhich embodies the principals of the invention;

FIGURE 2 is an elevational view with a portion of the burner shieldbroken away to show the details of the rail heater in the neighborhoodof the ignition cup;

FIGURE 3 is a cross-sectional view of the rail heater takensubstantially along the line 3-3 of FIGURE 2; and

FIGURE 4 is a cross-sectional view of the rail heater takensubstantially along the line 44 of FIGURE 2.

The arrangement contemplated by the present invention is a distributedline or ribbon type gas burner, which is adapted to heat an elongatedsection of rail-typically 11 to 17 feet long. The rail section to beheated, shown generally in FIGURE 1 at 11, is of typical shape andincludes an enlarged upper portion or ball 12, an intermediate verticalweb 13, and a horizontally flared base section 14.

Mounting holes are drilled through the web 13 at approximately twentyinch intervals as shown at 16. A bolt 18, washer 19, lock washer 20, andnut 21 are used to aflix the lower L-shaped member 23 of a bracketassembly to the web 13 of the rail. As shown best in FIGURE 4 of thedrawings, the stud 18 passes through a longitudinal slot in the bracketmember 23. The horizontal slot permits the bracket member 23 to bepositioned in various vertical positions. When the bracket member 23 isbolted in position flush against the web 13, an upper L-shaped bracketmember 24 is permitted to move toward and away from the Web 13 throughthe provision of an elongated slot of the outwardly extending flange ofthe member 23. A stud 27, washer 28, lockwasher 29 and a nut 30 aretightened to hold the upper and lower bracket members 23 and 24respectively together. The upwardly extending flange on the upperbracket member 34 is provided with a horizontally oriented elongatedslot through which passes a Nelson stud 33 which is welded to the backof a burner hood 35. A washer 36, a lockwasher 37 and a nut 38 affix thehood 35 to the bracket member 24.

The Nelson stud 33 is sufficiently long to extend well beyond the member24 in order to provide a point to which a burner shield 40 may beaffixed. A washer 41 is placed between the burner shield 40 and the nut38 while a lock washer 43 and a nut 44 are tightened to hold the burnershield in place.

It should be understood that while only one mounting bracket assemblyhas been described in detail, these assemblies are placed in intervalsalong the lengths of the rail heater to provide adequate support for theburner. The longitudinal slots which are incorporated into the L-shapedmounting bracket members 23 and 24 allow substantial relative movementbetween the rail and the mounted burner assembly, thereby permittingaccurate placement of the flame even though the mounting holes in web 13may not have been accurately positioned.

As best shown in FIGURE of the drawings, the burner chamber itself isformed by the combination of a burner hood 35 and a burner plate 45. Theburner hood 35 includes an arcuate portion shown generally at A whichsurrounds and is spaced from the top of gas carrying conduit 39 and adownwardly extending portion shown generally at B which is supported bythe upper mounting bracket 24. The angle shaped burner plate 45 ismounted at an angle to and spaced from the downwardly depending portionof the hood 35 to form an air intake opening between the bottom edge ofthe plate 45 and the hood 35. The long dimension of the upper edge C ofthe burner plate 45 is parallel with and spaced apart from the longdimension of the edge D to produce an elongated throat. The planes ofthese two edges form an acute angle with one another to create a venturieffect at the elongated throat. Gas is carried down the conduit 39 andis ejected through angle drilled jet openings of the type shown at Ewhich are positioned adjacent to the venturi throat. These jet holes arepreferably drilled tangential to the inside circumference of the conduit39 as shown in FIGURE 5.

Proper flow of combustion air and good mixing of gas and air are aidedby the non-radial drilling of the jet openings as shown at E in FIGURE5. Good air flow inside of the mixing chamber is enhanced by spacers 47and 48 which insure properly proportioned air passages. The spacer 47 isdirectly welded to the burner hood 35 while the spacer 48 is welded tothe burner plate 45. These spacers are positioned together and welded(typically at 6 to 12 inch) intervals along the length of the burnerassembly. The jet openings E may be spaced at intervals (e.g. 1 to 2inches apart).

The burner shields 40 are positioned as low as possible. If desired, theshields may rest on the wooden cross ties. In this position, most of theair enters at the top through the spacing between the shield 40 and thedownwardly extending portion of hood 35. The resulting enclosed chamberserves to concentrate the heat at the web of the rail and enhance smoothair flow into the venturi throat formed at edges C and D and permitsrecirculation of some of the products of combustion to the air intake.

As shown in FIGURES 1 and 2 of the drawings, the conduit 39 is split inthe middle with a T-joint 50 to which is connected a piping assembly 51.Gas is supplied to the conduit 39 from an available source through thepiping assembly 51. Due to the novel configuration employed, this gasneed not be' supplied at high pressurepressures as low as inch watercolumn being sufiicient. An aperture 54 is cut into the right handburner shield 40 to permit passage of the piping assembly 51.

The burner hood 35 and burner angle 36 are cut away in this centralportion of the heater to allow room for an ignition assembly whichincludes an ignition hood 60 and an ignition cup 61. A pair of Nelsonstuds 57 and 58 are welded to the two sides of the burner hood 35 inorder to mount this ignition assembly.

As shown in FIGURE 2 of the drawings, the ignition cup 61 is positionedimmediately below the conduit 39. As shown in FIG. 1, one wall of thecup 61 is formed by the igntiion hood 60 to which the cup 61 is Welded.A vertically drilled jet opening not (shown) in conduit 39 injects a rawgas jet into cup 61. A spark plug 65 is positioned within a mountingaperture in the ignition shield 60 such that the spark gap of plug 65projects into the ignition cup 61. The air and gas mixture in ignitioncup 61 is ignited by applying a high voltage to the spark plug 65 by wayof a conductor 66 which is connected to the secondary output winding ofa transformer 67 shown in FIG- URE 1. The transformer 67 is placedinside a protective housing having side and bottom walls 70 and a top72. A sealing gasket 73 is sandwiched between the top 72 and the housing70 to prevent entrance of moisture. The housing 70 is fastened directlyto the ignition shield 60 by means of a pair of extended stabilizingrods 74 and 75. A spacing block 76 made of ceramic material or the likeand having a longitudinal passage therethrough serves to insulate thetransformer 67 from heat transfer from the burner assembly, protects thehigh voltage conductor 66 from damage, and prevents inadvertent contactby operating personnel with the dangerous voltage appearing on conductor66. A rubber shroud 80 protects the electrical connection between thespark plug 65 and the high voltage conductor 66.

The primary of transformer 67 is energized by the voltage on conductors81 through a thermostat 82 which is affixed to the inside of the housing70. The thermostat 82 is provided with a remote sensing element 83 whichis held in the flame produced by the burner. The sensing element 83opens the primary circuit of the transformer 70 whenever the flame ispresent and closes the primary circuit to cause sparking at the gap inspark plug 65 whenever the fiame is absent. In this manner any flame-outis automatically sensed to cause re-ignition.

It is to be understood that the embodiment of the invention which hasbeen described is merely illustrative of one application of theprinciples of the invention. Numerous modifications may be made by thoseskilled in the art without departing from the true spirit and scope ofthe invention.

What is claimed is:

1. An arrangement for melting collected ice and snow from a railwayswitching rail which comprises, in combination,

a gas-carrying conduit spaced apart from and substantially parallel tothe long dimension of said rail,

jet holes drilled at intervals along said conduit,

means for supplying pressurized combustible gas to said conduit,

an elongated burner hood having an upper portion which surrounds and isspaced from the top of said conduit and a downwardly depending portionwhich extends below said conduit,

an elongated burner plate mounted at an angle to and spaced from saiddownwardly depending portion of said hood to form an air intake openingbetween the bottom edge of said plate and the downwardly extendingportion of said hood, the upper edge of said plate being spaced apartfrom the edge of said arcuate portion of said hood to form alongitudinal throat adjacent to said rail, and

means for igniting the gas-air mixture appearing at said throat.

2. An arrangement as set forth in claim 1 including an elongated burnershield which is mounted substantially parallel to and spaced from theplane of the downwardly depending portion of said hood on the side ofsaid hood opposite from said rail, whereby combustion products arerecirculated to said air intake.

3. An arrangement as set forth in claim 1 wherein the burner hood isspaced from the rail and the plane of the upper edge of said plate formsan acute angle with the plane of the edge of said arcuate portion toprovide a venturi effect at said throat which helps to prevent blow outof the flame of the burner and which is located adjacent the rail.

4. An arrangement as set forth in claim 3 wherein said conduit iscylindrical and wherein said jet holes are drilled tangential to theinner circumference of said conduit.

5. An arrangement as set forth in claim 1 wherein said means forigniting the air-gas mixture appearing at said throat comprises, incombination,

a cavity positioned adjacent to said conduit,

an opening in said conduit for injecting a gas jet into said cavity, and

electrical igniting means mounted within said cavity for igniting thegas within said cavity. 6. An arrangement for heating a railwayswitching rail which comprises, in combination,

a source of a combustible gas, an elongated conduit connected to saidsource, an elongated hood member having the cross-sectional shape of aninverted I, support means for mounting said hood such that its longdimension is parallel with said conduit, its upper arcuate portion ispositioned above, around, and spaced from said conduit and itsdownwardly depending portion extends below said conduit, an elongtaedplate mounted at an angle to the plane of the downwardly dependingportion of said hood,

the lower edge of said plate being spaced from said downwardly dependingportion to form an air intake, the upper edge of said plate beingparallel with and spaced from the edge of said arcuate portion to forman elongated throat,

jet holes provided at intervals along said conduit for directing saidgas toward said throat, and

means for igniting the gas-air mixture appearing at said throat.

7. An arrangement as set forth in claim 6 wherein said elongated throatis positioned parallel with and spaced from said rail.

8. An arrangement as set forth in claim 7 including a burner shieldwhich is mounted substantially parallel to and spaced apart from saiddownwardly depending portion of said hood on the side of said hoodopposite from said rail to cause combustion products produced at saidthroat to recirculate to said air intake.

9. An arrangement as set forth in claim 8 wherein the plane of the upperedge of said plate forms an acute angle with the plane of the edge ofsaid arcuate portion to produce a venturi effect at said throat.

10. An arrangement as set forth in claim 9 wherein said conduit iscylindrical and wherein said jet holes are drilled along a tangent tothe inner circumference of said conduit.

11. An arrangement as set forth in claim 6 wherein said means forigniting the air-gas mixture appearing at said throat comprises, incombination,

a cavity positioned adjacent to said conduit,

an opening in said conduit for directing a jet of gas into said cavity,and

electrically energized igniting means for igniting the gas in saidcavity.

References Cited UNITED STATES PATENTS 6/ 1938 Reynolds 246-428 7/1953White 246-428

